Questions tagged [odds-ratio]

A measure of association between two binary variables equal to the odds of a 'positive' outcome in 1 variable divided by the odds in the other. The OR ranges (0, infinity). It has a strong connection to logistic regression.

Filter by
Sorted by
Tagged with
0
votes
0answers
7 views

Vertical translation of independent variable vs OR and independent variable vs RR curve

i have been trying to predict risk of developing a cancer from genetic data. At the end I plotted a curve, that shows odds ratio (OR) and relative risk (RR) as a function of polygenic risk score (PRS) ...
0
votes
0answers
7 views

What is the difference between standardized mortality ratio (SMR) and odds ratio (OR) from age matched case and controls?

My question refers specifically to comparisons of chronic diseases, say heart failure (HF), between a specific group of interest (eg, diabetics) and a reference group (non-diabetics). SMR is the ...
0
votes
1answer
17 views

Odds Ratio Interpretation and Predicted Probabilities

I am conducting research on the association between smoking and Tuberculosis (TB), and I need to clarify what the odds ratio is telling me. I am getting the Odds Ratio value from the table of a ...
1
vote
1answer
31 views

Generate odds ratios across deciles / quantiles of an indpendent variable

With reference to the following figure from Bellomo et al., 2011: How exactly are the odds ratios across the deciles 'referenced against the 4th decile' calculated? My initial impression is that a ...
0
votes
0answers
10 views

Derivation of variance of Odds Ratio in a 2x2 table

Assuming that the elements of a 2x2 table (a,b,c,d) are binomial in distribution with a being $Bin(n_1,p_1)$ and c being $Bin(n_2,p_2)$. How can we show that $\hat {var(logOR)} = \frac 1 a + \frac 1 b ...
1
vote
1answer
18 views

How to interpret odds ratio with continuous independent variable (%) that have categories in different columns?

I am using a logistic regression to model a 0/1 event with community characteristics as being my explanatory variables but my data structure is different making the interpretation hard. My unit of ...
0
votes
0answers
7 views

Interpreting Odds Ratios for non-binary outcomes [duplicate]

I'm looking to interpret odds ratios with a quaternary outcome. Specifically, I'm trying to predict students' ratings of fairness (ordinal from Likert scale, 0-3) on a particular exam, based on the ...
1
vote
1answer
45 views

Interpreting odds ratios in ordinal logistic regression

I am trying to predict exam performance (below, average, above) based on whether participants attended a revision class. I am analysing my data in R using a proportional odds logistic regression. I am ...
0
votes
1answer
17 views

When Can I say odds ratio is important to analyze my data

Lets say in my data if I generate odds ratio between 2 variable A and B and get that the odds ratio is 2-5 is that a good thing to dive deep further or should I move to other relations .
0
votes
1answer
23 views

High odds ratio for composite score created by ridge regression

This question is a follow up to one of my previous questions asked on this site. The goal was to create a composite score for biomarkers related to a binary outcome and then use that in a regression ...
4
votes
1answer
87 views

Use example to explain odds ratio to layperson audience

I found an example of how to express odds-ratios in plain english. Here is the link http://www.pitt.edu/~bertsch/risk.pdf It says: How does one express an OR of 0.15 in plain English. Had this ...
0
votes
1answer
28 views

Interpreting a very small odds ratio when the Fisher's exact test is significant

I'm having a hard time interpreting odds ratios (OR) for a 2x2 contingency table. ...
2
votes
1answer
57 views

Group level effects (odds ratio) - dummy coding vs. effect

I ran a logistic model in R's brms, with a categorical variable (condition) with two levels as predictor. When interpreting the ...
0
votes
1answer
27 views

Log odds Standard Error

I am reading a paper on how the authors calculate the variance/standard deviation of what appears to be log(odds). The paper is a medical paper (Discontinuation of Oral Antivirals in Chronic ...
0
votes
0answers
29 views

Correct interpretation of odds ratio

I am wondering what the correct way of interpreting an odds ratio is. For example, suppose we have that the probability of success is $p=0.8$. Then, the odds ratio is: $$ \frac{p}{1-p} = \frac{0.8}{0....
0
votes
0answers
24 views

Odd Ratios Change After Including Other Independent Variables… What does that exactly mean?

I am currently writing my master's thesis and I want to identify whether Austrians living in Vienna are more likely than immigrants in Vienna to become self-employed. In order to find out whether this ...
0
votes
0answers
38 views

How to interpret multinomial regression results? [duplicate]

I want to investigate the relationship between stock traders' past success rate (i.e. the number of total winning trades divided by the total trades executed) on the status of their current trading ...
0
votes
1answer
22 views

When to exponentiate: the mean of the chain or at every step in the chain?

I am interested in when it is best to exponentiate a difference in log-odds Here is a sample problem in the stan language, three groups of forty binary observations, group 1 with hit probability = 0....
1
vote
1answer
57 views

Interpreting odd's ratios

If A is a binary faction (1 A and 0 not A) and if the odds ratios of A to B is (say) 1.2409 (24 percent or e ^ 0.2158). Then is the odds ratio of B to A 76% or 1 – 0.24?
0
votes
1answer
59 views

Odds ratio confidence intervals and p-values suggest different conclusions in a binary logistic mixed-effects model (glmer)

I am running a generalized linear mixed-effects model in R using the glmer function of lme4. The outcome variable is trial-level accuracy in a task (incorrect trials are 0, correct trials are 1), and ...
0
votes
0answers
31 views

Effect size in linear mixed models

Thank you for reading this question. I know there have been a few discussions regarding this topic, but I couldn't get a satisfactory answer. So here is my question, with some details in the ...
1
vote
1answer
52 views

Baffled by inconsistency between 95% CI for OR and p-value

I am using logistic regression to model the effect of two production variables on the occurrence of tuberculosis. My independent variables are A (farm size: 0 for small, 1 for large) and B (cattle co-...
1
vote
0answers
31 views

Ratio as independent variable for logistic regression

I am trying to model the association between "previous 2 year history of no shows for consult (independent variable)" with current no shows (dependent variable) using a logistic regression model. The ...
0
votes
1answer
45 views

Convert odds ratio back to logit - logistic regression

I'm attempting to convert odd's ratios reported in results back to their original logit form. From what I've gathered, the appropriate formula to do so is: ...
3
votes
2answers
179 views

Does the “divide by 4 rule” give the upper bound marginal effect?

In the logisitic regression chapter of "Data Analysis Using Regression and Multilevel/Hierarchical Models" by Gelman and Hill, The "Divide by 4" rule is presented to approximate average marginal ...
0
votes
0answers
11 views

Relative Risk Constraint?

I am starting to dig into some epidemiology and am just starting to get into the nuances of relative risk (RR) vs. the odds ratio (OR). In the Fundamentals of Biostatistics, I read: "Although ...
0
votes
2answers
156 views

Interpreting infinite odds ratio and confidence interval from Fisher's test

I've performed a two-sided Fisher's exact test on the following data, and the results include Infinity for the upper confidence interval and odds ratio. Are these results erroneous, and if not how do ...
0
votes
0answers
19 views

Interpretation of chisquare and odds ratio

I am studying te association between variables and used the chisquare test and the odds ratio of fisher exact test. I would like to know the exactly interpretation that i can do. The main variable is ...
0
votes
0answers
22 views

Multiple risk ratio analysis or single multiple logistic regression for survey

I was asked by a doctoral student to analyze the answers to an old questionnaire her lab has and would like to publish the results of. There are a few questions with regards to animal care and disease ...
0
votes
1answer
32 views

Comparing odds ratios of the same predictors and the same outcome across category of gender

I have two logistic models assessing the correlates of a binary outcome in males and females, respectively. The predictors are the same in both groups. I want to see if the effects of the predictors ...
1
vote
0answers
13 views

Meta-analysis for case-control studies, confounding factors

Is there a way to adjust the pooled summary effect size (odds ratio) for confounding factors while performing a meta-analysis in R studio? I am performing a meta-analysis and I don't want to pool ...
0
votes
0answers
31 views

What test to use to compare two proportions (and calculate effect size and confidence interval)?

There are many related questions here and elsewhere, but I found no satisfying answer. There are plenty of related tests and concepts: Z-test, chi-squared test, G-test, McNemar's test, Fisher's exact,...
0
votes
0answers
23 views

Regarding interpretation of Odds Ratio

I have just read in my professor's lecture notes that the Odds ratio $\psi(x)$ takes non-negative values, and that the the effect of $X$ (the predictor) on $Y$ (the binary target variable) is measured ...
0
votes
0answers
26 views

Probability of association in logistic regression models

I’m using a logit model to evaluate the association of a set of habitats (H) to a particular land cover. Both land cover and H are binary variables. ...
2
votes
1answer
243 views

How does fisher.test calculate the confidence interval for the odds ratio in R?

The fisher.test function in base R by default returns a confidence interval for the odds ratio in a 2x2 contingency table. For example: ...
0
votes
1answer
15 views

Strange odds ratio (OR) derived from Fisher's test

I have frequency data for about 1000 genetic marker for two groups that I want to compare them between the two groups. I used Fisher’s test (in R) on the count data and got FDR and odds ratio (OR) for ...
0
votes
0answers
20 views

Creating a Weighted Ratio Based On Size of Customer

I am attempting to created a weighted ratio/score for customers based on the number of support tickets they have entered in a time period against the number of units they have in service with us. ...
0
votes
0answers
27 views

1D Bayesian Inference clarification

I'd like some help making sure I understand a 1D Bayesian inference problem. Say I have a data vector which is an array of the number of flu cases reported weekly in California for the past 10 years. ...
0
votes
0answers
7 views

predict important markov chains(paths to an event) with confidence

I need help in validating my current approach as well as find any alternative approaches I could use in order to tackle issues like below. I have a dataset like below and I need to find important ...
2
votes
1answer
60 views

Odds ratio not between the two odds ratio of a stratified analysis

This is not the first time I have performed stratified analyses based on logistic regressions, but I have never before been confronted with this situation. When I test my relationship in the overall ...
2
votes
0answers
54 views

Odds Ratio, More Likely vs. As Likely, do I need to subtract 1?

When reporting odds ratios from a logistic regression, I've seen the words "as likely" and "more likely." If the odds ratio is say 3.5, I know that I can say females are 3.5 times as likely as males ...
0
votes
0answers
21 views

How to compare odds ratios across stratified sub-groups

From a randomized controlled trial, I have odds ratios (ORs) of disease A for an intervention vs control group. I want to see if the OR differs according to deprivation. I plan to stratify my study ...
1
vote
0answers
37 views

Interpretation of two odds ratios derived from two different cohen's ds, comparability for meta-analysis?

I have a question regarding the conversion of cohen's d into odds ratio (OR) and the comparability of results from two different situations. I wonder if the ORs derived from the two situations can ...
0
votes
0answers
8 views

reversal of odds ratios in covariate adjusted model

I am using a survey weighted GLM in R for a binary outcome. The raw risk ratio and the unadjusted ORs suggest that group 2 has significantly lower risk/odds. In the covariate adjusted model, the ...
0
votes
1answer
26 views

Converting OR to probabilities

I'm trying to understand some of my data in a logistic regression. I plotted headache (yes/no) vs. age and get an OR of 0.95. Now I realize this means that for every year 'younger', you have a 0.95 ...
0
votes
0answers
36 views

Conclusion for not rejecting a null hypothesis

I'm actually quite confused what is the outcome we could deduce here for the other exercise types listed in the diagram. From my interpretation, the null-hypothesis is: There is no association ...
2
votes
1answer
69 views

How does non-response bias affect the Confidence Interval

I asked earlier what is the idea behind putting up Table 3. I have a follow up question on how non-response bias identified can justify the different sizes of Confidence Interval(CI) in Figure 3. My ...
0
votes
1answer
16 views

The effect of a lack of dose-response results on odds ratio

This is part of a quantitative reasoning assignment I was working on. The study hypothesized that exercise may reduce the risk of disability for activities of daily living(ADL). However after ...
0
votes
1answer
26 views

Deriving the values of the range around the mean value

This is part of a bigger quantitative reasoning assignment I was working on. My understanding here is that the upper bound and lower bound of the ranges for each of the exercises should be reflected ...
1
vote
2answers
476 views

How do I interpret the odds ratio of an interaction term in Conditional Logistic Regression?

I am wondering what the correct interpretation of the odds ratio of an interaction term in conditional logistic regression is. Let's say there are two independent variables A and B, as well as an ...